Method of monitoring static charge

ABSTRACT

A method of monitoring static charge is provided. The method includes the operations as follows. A metallic plate is connected to a conductive tape wrapped around an outer surface of a non-conductive tube. A plurality of static charges are detected from the metallic plate by an electrostatic field meter, wherein the conductive tape and the metallic plate are entirely disposed within a metallic box. A flow rate of a fluid flowing through the non-conductive tube is adjusted according to the plurality of static charges detected by the electrostatic field meter.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation application of prior-filedU.S. application No. 16/883,947, filed May 26, 2020, and claims thebenefit of prior-filed U.S. provisional application No. 62/926,249,filed Oct. 25, 2019, under 35 U.S.C. 120.

FIELD

The present disclosure relates to a monitoring system and a method ofmonitoring static charge, and more particularly, to a monitoring systemand a method of using the same that may monitor the amount of staticelectricity or static charges and analyze a relationship between a fluidand a surface of a tube regarding the effect of arcing on flow rate.

BACKGROUND

Static electricity is produced by the build-up of electrons on weakelectrical conductors or insulating materials. These materials may begaseous, liquid or solid and may include flammable liquids, powders,plastic films and granules. The generation of static may be caused bythe rapid separation of highly-insulated materials by friction or bytransfer from one highly-charged material to another in an electricfield by induction.

Electrostatic discharge (ESD) is the sudden flow of electricity betweentwo electrically-charged objects caused by contact, an electrical shortor dielectric breakdown, and may be sufficient to cause serious electricshock. In the field of semiconductor manufacturing, static controlprograms have been carefully applied throughout the backend processes ofsemiconductor assembly operations due to the known problems ofelectrostatic discharge damage causing yield and reliability issues.However, the issue of static electricity may become more serious in someadvanced semiconductor manufacturing processes.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It shouldbe noted that, in accordance with the standard practice in the industry,various structures are not drawn to scale. In fact, the dimensions ofthe various structures may be arbitrarily increased or reduced forclarity of discussion.

FIG. 1 illustrates a stereo schematic view of a monitoring systemaccording to some embodiments of the present disclosure.

FIG. 2 illustrates a stereo schematic view of a monitoring systemaccording to some embodiments of the present disclosure.

FIG. 3A illustrates a stereo schematic view of a portion of a monitoringsystem according to some embodiments of the present disclosure.

FIG. 3B illustrates a stereo schematic view of a portion of a monitoringsystem according to some embodiments of the present disclosure.

FIG. 4 illustrates a stereo schematic view of a monitoring systemaccording to some embodiments of the present disclosure.

FIG. 5 illustrates a pipeline diagram of a semiconductor manufacturingsystem according to some embodiments of the present disclosure.

FIG. 6 illustrates a flow chart of monitoring static charge according tosome embodiments of the present disclosure.

FIG. 7 illustrates a flow chart of monitoring static charge according tosome embodiments of the present disclosure.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of elements and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting, For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper,” “on” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

As used herein, although the terms such as “first,” “second” and “third”describe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be only used to distinguishone element, component, region, layer or section from another. The termssuch as “first,” “second,” and “third” when used herein do not imply asequence or order unless clearly indicated by the context.

In the field of semiconductor industry manufacturing, the processes suchas photolithography and wet etching have become more sensitive to metalsat advanced process nodes. As a result, extracted metals from chemicaldelivery systems may cause critical wafer defects and impact productionyields. example, some factories utilize non-metal materials influid-handling systems to reduce amounts of extracted metals in theprocess chemicals; however, the increased use of non-metal materialssuch as fluoropolymer raises concern for electrostatic discharge incomponents. Particularly, solvents used in the semiconductor industryhave low conductivity, which enables them to generate and holdelectrical charge.

To be more detailed, there are several high-resistance fluids widelyused in semiconductor manufacturing processes, such as butyl acetate andpropylene glycol monomethyl ether acetate (PGMEA). Such fluids mayinduce static charge when passing through a component made of materialshaving resistances different from those of the fluids (e.g.,polytetrafluoroethene (PTFE)) due to friction, and electrical dischargeor arcing may occur accordingly.

More precisely, a low-conductivity fluid flowing in a non-conductivetube or component (e.g., a diaphragm pump) may cause charge separationat the interface of the fluid and the tube. As a result, negativecharges may be generated or accumulated at such interface, and positivecharges and negative charges in the tube may be generated or accumulatedrespectively in proximity to the inner surface and the outer surface ofthe tube. Such separation of charge is similar to the phenomenon thatoccurs when two materials move with respect to each other and thecharges are transferred at the interface.

There are several factors that a affect the static charges generated oraccumulated in a tube or component made of a non-metal material. Forinstance, the generation or accumulation of static charges may beincreased when the inside diameter, the length, or the resistance perunit length of the tube are increased. Furthermore, the dielectricconstant, the volume resistivity, and the surface resistivity of thematerial of the tube may also increase the generation or accumulation ofstatic charges. On the other hand, the increase of the conductivity ofthe tube material may decrease the generation or accumulation of staticcharges.

In some circumstances, for example, when the flow rate ofhigh-resistance fluid such as butyl acetate is too high (e.g., exceedingabout 0.7 m/s), the amount of static charges and the total staticelectricity will increase accordingly. Point discharge may occur as aresult and cause arcing, which may produce contamination particles andaffect product yield.

In considering the damage to components that the electrical discharge orarcing may cause, and the contamination of the wafer by particles due tosuch damage, the amount of static charges or the total value of staticelectricity of the fluids should be monitored for determining whether totake further action, such as real-time reduction of the flow rates ofthe fluids.

In the field of fluid monitoring, generally, the high-resistance fluidsare often volatile solvents, and thus the off-line sampling iscomplicated and dangerous. In addition, the off-line sampling may not becontinuously performed, and the background value of the staticelectricity may easily be affected by a magnetic field and/or anelectrical field from a nearby human body. Moreover, the electriccharges at the surface of the tubes made of non-metal materials are noteasily moved, so the distribution of potential at the surface of thetubes is not even. As a result, the measurement result provided by anelectrostatic field meter may be inaccurate.

Accordingly, some embodiments of the present disclosure provide amonitoring system and a method of monitoring static charge to replacethe off-line sampling. In some embodiments, the monitoring systemdisclosed in the present disclosure may include a conductive tape,wrapped around an outer surface of a plastic tube, and connected to ametallic plate. The static charges may be collected by the conductivetape, induced to the metallic plate and detected by an electrostaticfield meter. A real-time alarm may be set to adjust the flow rateimmediately and automatically when the electrostatic value exceeds apredetermined value, so that the flow rate can be adjusted in accordancewith the change of the amount of static charges. In some embodiments,the real-time alarm includes a valve for adjusting the flow rate, whichmay be operated automatically or manually.

More precisely, the static charges generated by the friction between thehigh-resistance fluids and the plastic tubes, pumps or other componentsare collected by the conductive tape, and the metallic plate connectedto the conductive tape may be used as an antenna for the detection. Theelectric field generated by the static charges on the metallic plate maybe detected by the infrared sensor of the electrostatic field meter. Inorder to avoid the conditions that lead to electrical discharge andarcing, the data collected or generated by the electrostatic field metermay be transmitted to a computer. Such computer may control the flowrate of the high-resistance fluids in the plastic tubes automatically bysending the instruction to slow down or stop the pumps nearby before anaccumulation of static charges exceeds a breakdown voltage of thematerial of the tube or the pump (i.e., the breakdown is not triggeredby the accumulation of static charges). The relationship between thestatic charge and the voltage may be illustrated as Q=C*V, wherein Q isthe amount of charge, C is the capacitance, which refers the amount ofcharge may be held or stored by an object, and V is the voltage.Accordingly, the static charge is proportional to the voltage.

FIG. 1 illustrates a stereo schematic view of a monitoring systemaccording to some embodiments of the present disclosure. As shown in thefigure, the monitoring system 1 may include a conductive tape 10, ametallic plate 20, an electrostatic field meter 30, and a non-conductivetube 40. The non-conductive tube 40 includes an outer surface 40A. Theconductive tape 10 is configured to wrap around the outer surface 40A ofthe non-conductive tube 40. The metallic plate 20 contacts theconductive tape 10 and extends away from the conductive tape 10. Theelectrostatic field meter 30 is disposed a predetermined distance awayfrom the metallic plate 20, and thus a static charge of the metallicplate 20 is thereby detectable by the electrostatic field meter 30.

In some embodiments, the non-conductive tube 40 is configured fortransporting fluids, wherein each fluid has a resistance greater than aresistance of the non-conductive tube 40. As previously mentioned, thegeneration or accumulation of static charges may be affected by theproperties of the tube; in fact, the properties of the fluid may alsoaffect the generation or accumulation of static charges. For instance,when the flow velocity, the resistance, the dielectric constant, or therelaxation time constant of the fluid is increased, the generation oraccumulation of static charges may be increased concurrently. On theother hand, when the resistance of the fluid is decreased, theconductivity of the fluid is increased, and the generation oraccumulation of static charges may be decreased also.

Because the properties of both the tube and the fluid may affect thegeneration or accumulation of static charges, in some embodiments, thecomprehensive effect of the amount of static charges is based on thedifference between the resistances of the tube and the fluid therein.That is, with greater resistance difference between the two materials,more static charges may be generated or accumulated near the interfacethereof, and more serious electrical discharge or arcing may occur.

The static charges on the non-conductive tube 40 may be accumulated bythe conductive tape 10. In some embodiments, the conductive tape 10 iswrapped around the non-conductive tube 40, rather than simply attachedto the non-conductive tube 40 without surrounding the surface thereof.In such embodiments, it may be ensured that all of the static charges atsuch section of the non-conductive tube 40 (i.e., a first width W1 ofthe conductive tape 10) are accumulated completely. The conductive tape10 may be made by applying an electrically conductive adhesive to adurable, flexible support body. In some embodiments, the conductive tape10 is made of copper foil or aluminum foil with anelectrically-conductive acrylic adhesive.

Generally, the tubes used in factories for transporting fluids are madeof plastic materials such as polytetrafluoroethene (PTFE),perfluoroalkoxy alkanes (PFA), polyvinyl chloride (PVC), chlorinatedpolyvinyl chloride (CPVC), unplasticized polyvinyl chloride (UPVC), andthe like. In some circumstances, the tubes may be made of plasticmaterials with glass fibers such as fiber-reinforced plastic (FRP). Aspreviously mentioned, the static charges generated may not move alongthe surface of plastic tubes, and exhibit similar behavior on the tubesmade of non-metal materials. Accordingly, it is not possible to overcomethe issue of electrical discharge or arcing simply by inducing theunwanted static charges to the ground through a ground wire. Therefore,there is a need to monitor such static charges in order to avoid theoccurrence of electrical discharge or arcing.

In some embodiments, the static charges collected by the conductive tape10 may be induced to the metallic plate 20. The metallic plate 20 may bemade of metal antenna materials such as copper, copper alloy, aluminum,aluminum alloy, or the like. In some embodiments, the metallic plate 20extends perpendicular to the outer surface 40A of the non-conductivetube 40. In some embodiments, the first width W1 of the conductive tape10 is identical to a second width W2 of the metallic plate 20. In someother embodiments, the first width W1 of the conductive tape 10 is notidentical to the second width W2 of the metallic plate 20 but isidentical to the width of each of the other metallic plates 20 in thesemiconductor manufacturing system. That is, the distribution of thestatic charges in the metallic plate 20 is related to the size and shapethereof, and therefore the geometry of each of the metallic plates 20 inthe semiconductor manufacturing system may be aligned to ensure theconsistency of the monitoring result of the static charge in thesemiconductor manufacturing system.

In some embodiments, the tubes used in factories for transporting fluidsare made of metal such as stainless steel. The static charges may bemoved in the metal easily; however, if the metal tubes are not grounded,the static charges may accumulate at the outer surface of the tubes, andit is still possible to monitor the generation or accumulation of thestatic charge by the conductive tape wrapped around the outer surface ofthe tube and the metallic plate connected thereto.

In the present disclosure, the metallic plate 20 is utilized as anantenna for monitoring. The static charges distributed at the surface20A of the metallic plate 20 may be monitored by the electrostatic fieldmeter 30, which is disposed a predetermined distance away from themetallic plate 20. The electrostatic field meter 30 may be called astatic meter and may be utilized to measure the electrostatic field ofan object in volts without contact. In some embodiments, theelectrostatic field meter 30 may be used with a parametric amplifier.More precisely, the charges caused by electrostatic induction at theelectrostatic field meter 30 may be converted to an alternating currentwhich is proportional to the field strength, and the parametricamplifier may measure the current without loss in relation to the fieldstrength.

In some embodiments, the electrostatic field meter 30 may be fixed at aplace near the positions of the conductive tape 10 and the metallicplate 20. The fixing of the electrostatic field meter 30 may ensure thesuitable distance between the electrostatic field meter 30 and themetallic plate 20 is maintained, without being affected by shake or swayunder repeated manual measurements. As a result, for instance, themanual measurement such as one that uses a Faraday cup may be ruled out.In some embodiments, the electrostatic field meter 30 may be connectedto a power supply and hence it may be powered continuously.

In an external environment, the static electricity monitoring may begreatly affected by the electrical field and the magnetic field. Forinstance, the electric potential generated from friction by humanwalking may be as high as about 2000V, and therefore as shown in FIG. 2,in some embodiments, the monitoring system 1 of the present disclosuremay include a metallic box 50 covering the conductive tape 10 and themetallic plate 20 for shielding purposes. In some embodiments, themetallic box 50 includes an opening 501 aligned with the electrostaticfield meter 30 and the metallic plate 20 for monitoring, that is, theopening 501 faces the electrostatic field meter 30. Moreover, theopening 501 is disposed between the metallic plate 20 and theelectrostatic field meter 30, for instance, the opening 501 may at anintermediate point of a linear path between the metallic plate 20 andthe electrostatic field meter 30.

The metallic box 50 is utilized to create a Faraday cage and thus anexternal electrical field and/or a magnetic field (e.g., from theelectric charges on a moving human body) may cause the electric chargeswithin the conducting material of the metallic box 50 to be distributed,so that the electric charges may cancel the field's effect in theinterior of the metallic box 50. In other words, the components insidethe metallic box 50 may be shielded from the interference of theelectrical field and the magnetic field outside. In some embodiments,the electrostatic field meter 30 is fixed close to the opening 501 sothat most of the linear path between the metallic plate 20 and theelectrostatic field meter 30 is shielded by the metallic box 50. In someembodiments, the metallic box itself 50 is grounded.

As shown in FIG. 3A, in some embodiments, each end of the non-conductivetube 40 wrapped by the conductive tape 10 may be connected to anddisposed between a first metallic tube 401 and a second metallic tube402. In such embodiments, the non-conductive tube 40 is made ofnon-metal materials such as plastic. In other words, the non-conductivetube 40 made of plastic may be added to a semiconductor manufacturingsystem that uses mainly metallic tubes. In such embodiments, thenon-conductive tube 40 made of plastic may be utilized to monitor thestatic charge generated or accumulated within a specific section in thesemiconductor manufacturing system, even though the first metallic tube401 and the second metallic tube 402 are grounded. In such embodiments,the first width W1 of the conductive tape 10 may be less than a thirdwidth W3 of the non-conductive tube 40. so the conductive tape 10 maynot be in contact with the first metallic tube 401 and the secondmetallic tube 402. Otherwise, the electric potential of the metallicplate 20 will be measured as the ground potential instead of theelectrostatic potential.

As shown in FIG. 3B, in some embodiments, the non-conductive tube 40wrapped by the conductive tape 10 may be connected to a diaphragm pump60. The diaphragm pump 60, widely used in the semiconductormanufacturing system, is a positive displacement pump which may utilizetwo flexible diaphragms that reciprocate back and forth, creating atemporary chamber that both draws in and expels fluid through the pump.The diaphragms may work as a separation wall between the air and theliquid. The material of the diaphragm pump 60 includes plastic, andstatic charge may be generated or accumulated at the diaphragm pump 60due to the flow of the fluid. Therefore, the static charges generated oraccumulated at the diaphragm pump 60 may be monitored by thenon-conductive tube 40 wrapped by the conductive tape 10 beside thediaphragm pump 60.

As shown in FIG. 4, in some embodiments, the semiconductor manufacturingsystem may include a computer 70 coupled to the electrostatic fieldmeter 30. In such embodiments, the computer 70 may be used to adjust aflow rate of a fluid flowing through the non-conductive tube 40according to a data generated by the electrostatic field meter 30. Thatis, the present disclosure may monitor the amount of static charges andanalyze the relationship between the flow rate of the fluid (e.g.,chemical liquid with high resistance) and the arcing caused by thefluid. Accordingly, in some embodiments, a real-time alarm may be set toadjust the flow rate of the fluid automatically when an electrostaticvalue exceeds a warning value, so that the flow rate may be adjustedintelligently in accordance with the amount of static charges generatedor accumulated at the non-conductive tube 40. Furthermore, the metallicbox 50 previously shown in FIG. 2 may thus be utilized to avoid falsealarms caused by external interference.

The monitoring system of the present disclosure may be utilized in asemiconductor manufacturing system for maintaining the quality of thefluid for semiconductor processing. As shown in FIG. 5, in someembodiments, the semiconductor manufacturing system may include aplurality of tanks 701 and 702 and a plurality of non-conductive tubes40 configured to connect the plurality of tanks 701 and 702. In someembodiments, the plurality of tanks may include at least a first tank701. The first tank 701 is a lorry tank and is arranged at the front endof the semiconductor manufacturing system and is the tank for storingthe liquids from a lorry. That is, the chemical liquids transported bythe lorries may be first pumped into the first tank 701 for later use.In some embodiments, the monitoring system 1 includes the conductivetape 10, the metallic plate 20, and the electrostatic field meter 30 aspreviously shown in FIG. 1, disposed near the first tank 701. In someembodiments, the conductive tape 10 may be wrapped around the surface ofthe non-conductive tube 40 connected to an inlet 701A of the first tank701. The monitoring system 1 near the first tank 701 may be used tocontrol the flow rate of the fluid flowing from the lorry into the firsttank 701. If static charges are generated or accumulate quickly near theinlet 701A, arcing may thus occur, and the impurities or contaminantsgenerated thereby may contaminate the fluid in the first tank 701.Accordingly, in some embodiments, the flow rate of the fluid injectedinto the first tank 701 may be automatically adjusted in real time bythe computer 70 (previously shown in FIG. 4) based on the monitoringdata generated by the electrostatic field meter 30.

In some embodiments, the plurality of tanks may include at least asecond tank 702. Generally, the second tank 702 is a day tank and isutilized to store fuel, and in some embodiments, the second tank 702 maybe utilized to store the liquids for semiconductor processing. In orderto force the liquids out of the second tank 702, in some embodiments,some gases such as nitrogen (N₂) may be pumped into the second tank 702.Because the friction between the tube and the nitrogen gas may generatestatic charges, the objects monitored by the monitoring system mayfurther include the metallic plate on a gas tube, and the flow rate ofthe gas may be adjusted in real time based on the static chargesdetected by the electrostatic field meter. In some embodiments, theconductive tape 10 may be wrapped around the surface of thenon-conductive tube 40 connected to an inlet 702A or an outlet 702B ofthe second tank 702.

In some embodiments, the semiconductor manufacturing system may includeat least a pump 703 connected to the non-conductive tube 40, and theflow rate of the liquid pumped by the pump 703 may be adjusted in realtime according to the static charges detected by the electrostatic fieldmeter. Moreover, the pump 703 may include some components which are madeof plastics, and by adjusting the flow rate of the liquid (e.g., butylacetate), the voltage induced by the static charges generated oraccumulated at the pump 703 may be kept below a breakdown voltage of thematerial of the pump 703.

FIG. 6 illustrates a flow chart of monitoring static charge according tosome embodiments of the present disclosure. In some embodiments, themeasurement includes an operation 601: collecting a plurality of staticcharges from a conductive tape wrapped around an outer surface of anon-conductive tube; an operation 602: inducing the plurality of staticcharges to a metallic plate contacting and extending away from theconductive tape; and an operation 603: detecting the plurality of staticcharges by an electrostatic field meter disposed a predetermineddistance away from the metallic plate.

In performing the operations 601, 602 and 603, the monitoring systemdisclosed in FIG. 1 may be utilized, and the repeated descriptions ofthe features and functions of the monitoring system are omitted here forbrevity. In addition, in order to adjust the flow rate of the liquid inreal time, in some embodiments, the method of monitoring static chargemay further include operations that include transmitting a datagenerated by the electrostatic field meter to a computer and adjusting aflow rate of a fluid flowing through the tube by the computer.

In performing the operation of adjusting the flow rate in real time, insome embodiments, the flow rate may be decreased when the total voltageinduced by the plurality of static charges detected by the electrostaticfield meter is nearly equal to or greater than a breakdown voltage ofthe material of the non-conductive tube or a pump connected to thenon-conductive tube.

In the circumstances that the monitoring system in the presentdisclosure is used in a factory which includes a semiconductormanufacturing system, the operations of the method may refer to FIG. 7,which illustrates a flow chart of monitoring static charge according tosome embodiments of the present disclosure. Such method may include anoperation 701: wrapping an outer surface of each of a plurality ofnon-conductive tubes in proximity to a plurality of tanks by a pluralityof conductive tapes; an operation 702: placing a metallic plate on eachof the conductive tapes; and an operation 703: fixing an electrostaticfield meter a predetermined distance away from each of the metallicplates.

In performing the operations 701, 702 and 703, the semiconductormanufacturing system disclosed in FIG. 5 may be utilized, and therepeated descriptions of the features and functions of the monitoringsystem are omitted here for brevity. By wrapping the non-conductivetubes by the conductive tapes and using the metallic plate and theelectrostatic field meter in several positions, even though a greatquantity of high-resistance fluids are transported therein quickly andcontinuously, the change of the static charge generated or accumulatedin the semiconductor manufacturing system may be monitored easily,safely, and automatically.

According to the present disclosure, a monitoring system and a method ofmonitoring static charge are disclosed. In considering that a largeportion of tubes in factories are made of plastic, and the transportingof the chemical materials in the plastic tubes may generate staticcharges due to friction, particularly, when the resistance of thechemical materials are high, the present disclosure uses a conductivetape wrapped around an outer surface of a non-conductive tube toaccumulate the static charges, and uses a metallic plate connected tothe conductive tape as an antenna for monitoring. The static chargesinduced from the conductive tape may be distributed at the surface ofthe metallic plate and be detected by an electrostatic field meterdisposed a predetermined distance away from the metallic plate. Theelectrostatic field meter may provide a data to a computer for adjustinga flow rate of a fluid in the non-conductive tube. Accordingly, theamount of the static charges may be controlled by adjusting the flowrate in real time, and therefore the yield and productivity of thesemiconductor products may be enhanced because the generation of arcingor the contamination particles formed thereby may be alleviated oravoided.

In one exemplary aspect, a monitoring system is provided. The monitoringsystem includes a non-conductive tube, a conductive tape, a metallicplate, and an electrostatic field meter. The non-conductive tubeincludes an outer surface. The conductive tape is wrapped around theouter surface of the non-conductive tube. The metallic plate contactsand extends away from the conductive tape. The electrostatic field meteris disposed a predetermined distance away from the metallic plate, and astatic charge of the metallic plate is detectable by the electrostaticfield meter.

In another exemplary aspect, a method of monitoring static charge isprovided. The method includes the operations as follows. A plurality ofstatic charges are collected from a conductive tape wrapped around anouter surface of a non-conductive tube. The plurality of static chargesare induced to a metallic plate contacting and extending away from theconductive tape. The plurality of static charges are detected by anelectrostatic field meter disposed a predetermined distance away fromthe metallic plate.

In yet another exemplary aspect, a method of monitoring static charge isprovided. The method includes the operations as follows. A plurality ofstatic charges are detected from a metallic plate connected to aconductive tape wrapped around an outer surface of a non-conductive tubeby an electrostatic field meter. A flow rate of a fluid flowing throughthe non-conductive tube is adjusted to keep the plurality of staticcharges detected by the electrostatic field meter below a breakdownvoltage of material of the non-conductive tube or a pump connected tothe non-conductive tube.

The foregoing outlines structures of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A method of monitoring static charge, the method comprising: connecting a metallic plate to a conductive tape wrapped around an outer surface of a non-conductive tube; detecting a plurality of static charges from the metallic plate by an electrostatic field meter, wherein the conductive tape and the metallic plate are entirely disposed within a metallic box; and adjusting a flow rate of a fluid flowing through the non-conductive tube according to the plurality of static charges detected by the electrostatic field meter.
 2. The method of claim 1, wherein the plurality of static charges detected by the electrostatic field meter is reduced to lower than a breakdown voltage of material of the non-conductive tube or a pump connected to the non-conductive tube by adjusting the flow rate of the fluid flowing through the non-conductive tube.
 3. The method of claim 1, wherein the non-conductive tube comprises a plastic material with glass fiber.
 4. The method of claim 1, wherein the electrostatic field meter is fixed at a place having a predetermined distance away from the metallic plate.
 5. The method of claim 1, wherein the metallic box comprises an opening aligned with the electrostatic field meter and the metallic plate.
 6. The method of claim 1, wherein the metallic box is grounded.
 7. The method of claim 1, further comprising: setting a real-time alarm to adjust the flow rate of the fluid automatically when an electrostatic value exceeds a warning value.
 8. The method of claim 1, wherein the fluid comprises butyl acetate or propylene glycol monomethyl ether acetate.
 9. A method of semiconductor manufacturing, comprising: receiving a wafer with a material layer; applying a chemical fluid onto the material layer; and preforming an operation to the wafer, wherein the chemical fluid is provided by a tube made by a non-metal material, and a metallic plate disposed on the tube is configured to accumulate a plurality of static charges, wherein the plurality of static charges accumulated at the metallic plate are detected by an electrostatic field meter disposed a predetermined distance away from the metallic plate.
 10. The method of claim 9, further comprising: wrapping a conductive tape around an outer surface of the tube; and connecting the metallic plate to the conductive tape.
 11. The method of claim 9, wherein the chemical fluid comprises a volatile solvent.
 12. The method of claim 9, wherein the metallic plate is entirely disposed within a metallic box.
 13. The method of claim 12, wherein the metallic box comprises an opening aligned with the electrostatic field meter and the metallic plate.
 14. The method of claim 9, further comprising: adjusting a flow rate of the chemical fluid flowing through the tube to keep a plurality of static charges detected by the electrostatic field meter below a breakdown voltage of the non-metal material.
 15. A method of monitoring static charge, the method comprising: applying a fluid in a semiconductor manufacturing process through a non-conductive tube made of a material having a resistance different from the fluid, wherein a plurality of static charges generated by a friction between the fluid and the non-conductive tube are accumulated by a metallic plate extending away from the non-conductive tube; and detecting the plurality of static charges accumulated at the metallic plate by an electrostatic field meter disposed a predetermined distance away from the metallic plate.
 16. The method of claim 15, further comprising: wrapping a conductive tape around an outer surface of the non-conductive tube; and connecting the metallic plate to the conductive tape prior to detecting the plurality of static charges.
 17. The method of claim 15, wherein the metallic plate is entirely disposed within a metallic box, and the metallic box comprises an opening aligned with the electrostatic field meter and the metallic plate.
 18. The method of claim 17, wherein the opening is at an intermediate point of a linear path between the metallic plate and the electrostatic field meter.
 19. The method of claim 15, wherein the non-conductive tube is connected to a lorry tank arranged at a front end of the semiconductor manufacturing system.
 20. The method of claim 15, where in the material comprises polytetrafluoroethene. 